Traditionally most local telephone networks belonged to the same telephone company. This company was broken up into several Regional Bell Operating Companies (RBOC). These telephone service providers are now called Local Exchange Carriers (LEC). Every subscriber that has local (i.e.: not long distance, not cellular) telephone service is connected to a local telephone line 32 as shown in FIG. 1. The point of origin of the local telephone line is the LEC equipment 33. At the point of origin 33, the local telephone line 32 can be switched between different types of equipment or network interfaces using a switch matrix 30 of the type described by Kellock U.S. Pat. No. 6,259,676,B1, dated Jul. 10, 2001 or using the method described by King, US Patent Application US 2001/0040956 A1 dated Nov. 15, 2001. The switch matrix 30 can be an automatic device of the type described by Suzuki et al., U.S. Pat. No. 5,790,651, dated Aug. 4, 1998, or a manual connection block as described by Napiorkowski et al., U.S. Pat. No. 5,570,422, Dated Oct. 29, 1996. All the local telephone equipment from the local telephone switch 22 up to the demarcation point 34 shown in FIG. 1 belongs to a single service provider having one centralized network maintenance and control system 23 also called an Operation System (OS). The term local telephone network is used throughout this document to designate the equipment, the facilities and the operating system. The demarcation point 34 is the interface point between the customer-premises telephone line 36 and the service provider local network 35. The term Network Terminating Interface (NTE) is often a synonym of the demarcation point 34. To simplify the diagram, a telephone symbol 38 is used to represent any customer-premises telephone equipment in FIG. 1 to 4.
In the early 1990's, LECs started competing with other LECs by purchasing facilities (i.e. telephone lines) from selling LECs. FIG. 2 shows a customer-premises telephone line 36 connected to a local telephone line 32 that belongs to a LEC but is purchased by another LEC. As can be seen from FIG. 2, switching local telephone lines 32 with attached customer-premises lines 36 at the service provider end of the network can easily be accomplished by prior art equipment and methods 28, 30 described above or by maintenance personnel.
As the telecommunications industry evolved, Competitive Access Providers (CAPs) emerged to compete with LECs to offer subscribers local telephone service. The CAPs extended their telecommunication networks from the Local telecommunication Switch 22A up to the demarcation point 34A. FIG. 3 shows a subscriber that is serviced by two telephone service providers. Each service provider has a local telephone network 22 to 34 and 22A to 34A that terminates at demarcation points 34 and 34A at the subscriber's premises 39.
This new configuration creates a problem involving an expensive service call by maintenance personnel that wipes out any benefits to consumers afforded by competition in the local telephone industry.
When a subscriber changes from one service provider to the other, the telephone line 36 has to be physically disconnected from demarcation point 34 and re-connected to demarcation point 34A. For many reasons, it is not possible to connect both telephone lines in parallel 37 at the subscriber end with prior art equipment 30 and 30A such as Kellock or by using a the method described by King. One major reasons is that the local networks of the two service providers often have different electrical characteristics, some model of Network Elements (NE) 26A used by CAPs have a 24 Volts DC battery voltage with a local ground 29A while the LEC network may have a 48 volt DC battery voltage that is grounded at the originating end of the network 29. FIG. 3 illustrated a frequent network configuration where the LEC has a very long local telephone line 32 between its local switch 30 and the demarcation point 34 while the CAP has a short local telephone line 32A because the CAP has placed the Network Element 26A close the demarcation point 34A. King recognizes that telephone systems are not designed to operate with two lines in parallel in paragraph (0037) page 3 and goes on to state that maintenance personnel is still required although at a more convenient time.
While King claims the selling LEC gives control of the connection process to the purchasing LEC, FIG. 5, block S12 of his patent shows the purchasing LEC requesting a confirmation from the selling LEC effectively giving the selling LEC the capability to block or delay the transfer of the subscriber. While LECs tent to cooperate with each other, cooperation between a CAP and a LEC is less frequent. From a business perspective, the problem is easily understood; LECs selling and buying from each other are in a win-win situation. On the other hand, a CAP completely removes the subscriber and the revenue stream, leaving the LEC with an unused facility that still requires maintenance.
A telecommunications switch as described by Nolde, U.S. Pat. No. 5,920,615, dated Jul. 6, 1999 is also not feasible to eliminate service calls because it is designed to switch a plurality of normal communication apparatus on a single local telephone line using four wires. It does not take into account the requirement of multiple and electrically different local telephone networks as described above. In addition a Nolde-type master-slave system does not solve the equal access issues.
Powering equipment to switch telephone lines at the Demarcation Points 34 and 34A is also a serious problem not envisioned by any prior equipment. A LEC will not accept a piece of equipment in its network that is powered by local power 27A (often used by CAP service providers) while it has centralized diesel and battery backup facilities 27 with different, sometimes better, capabilities. This eliminates prior art equipment such as Meeske, U.S. Pat. No. 6,415,022 B1, dated Jul. 2, 2002. The Meeske equipment also adds tremendous complexity to the network. Each CAP and LEC would have to keep track of this equipment and its configuration in multiple locations. Errors of one company in programming such equipment could result in loss of service to a competitor's subscriber.
While using local AC power is not an option, using the telephone line power to operate equipment at the demarcation points 34 and 34A poses serious problems because that power is intended to operate customer-premises equipment such as telephones, fax machines, modems and CallerID devices that rely on the power available from the local telephone line such as described by Ninh, U.S. Pat. No. 6,212,274 B1, dated Apr. 3, 2001. The problem is compounded by maintenance equipment used by the service providers such as equipment described by Liu, U.S. Pat. No. 6,266,395 B1, dated Jul. 24, 2001.
It is an objective of this invention to solve the problems described above in a way defined in the independent claims.